There has been provided an image forming device that forms a visible image by supplying a developer to an electrostatic latent image formed on a photosensitive member and that transfers the visible image onto a recording medium. In this type of image forming device, in order to facilitate maintenance operation, a developing unit is configured as a developing cartridge that is detachably mounted on a main body of the image forming device. Because the time at which the photosensitive member becomes unusable due to deterioration with time differs from the time at which the developer is fully consumed, a photosensitive-member cartridge including the photosensitive member is provided separately from the developing cartridge so that these cartridges may be replaced according to their lifetime. These cartridges are attached to each other, forming a process cartridge, and the process cartridge is detachably mounted on the main body of the image forming device.
In Unexamined Patent-Application Publication No. 2001-75457, one of a pair of conveying rollers for conveying a recording medium is provided on the main body of the image forming device (hereinafter referred to as a “device-side conveying roller”), and the other one of the conveying rollers is provided on the photosensitive-member cartridge (hereinafter referred to as “cartridge-side conveying roller”). Therefore, the cartridge-side conveying roller separates from the device-side conveying roller by moving in the substantial horizontal direction when the process cartridge is detached from the main body of the image forming device.
Because the cartridge-side conveying roller needs to be properly brought into contact with the device-side conveying roller when the process cartridge is attached to the main body, the cartridge-side conveying roller is loosely supported on a cartridge casing of the photosensitive-member cartridge so as to be movable in the vertical direction with respect to the cartridge casing. For this reason, when the photosensitive-member cartridge is not mounted on the main body of the image forming device, the cartridge-side conveying roller rattles, thereby interrupting handling of the photosensitive-member cartridge. Also, when the cartridge-side conveying roller rattles, the cartridge-side conveying roller may protrude outside beyond the cartridge casing of the photosensitive-member cartridge due to its own weight.